Sensation sense organ"s response to external stimuli & responses transmitted to brain: elementary experience, w/o perceptual experiences, ex. light, air vibrations, odor not what object. Perception brain"s further process of detected signals: conscious internal representation of stimuli, construct info from sensation. Sensory coding sensory organ"s translation stimuli: physical properties. Neural impulses: transduction sensory receptors pass produce neural impulses when receive physical or chemical stimulation. Sensory receptors specialized neurons in sense organs. Connection neurons pass neural impulses to brain. Only sensory organ"s neurons directly respond w/ stimuli, brain respond to other neurons" input: different physical features has different neural impulse patterns. B/c brain can"t process raw stimuli: reception: most sensory thalamus, then thalamus cortex. Cortex = information interpreted as smell, sound, touch. Qualitative information diff. sensory receptors respond to qualitatively different stimuli ex. tuba vs. flute, red vs. green. Quantitative information same sensory receptor, different firing speed ex. higher freq. w/ brighter light, louder sound.